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Key-P Function - GF27.10-P-3028RFH

Transmission 724.2 in model 205, 253 

Function requirements, general 

IMPORTANT The electronic ignition lock control unit (N73) transmits the status of circuit 15 via chassis FlexRay (Flex E), powertrain control unit (N127) and drive train CAN (CAN C1) to the fully integrated transmission control unit (Y3/8n4) and to the CDI control unit (N3/9) (diesel engine) or to the ME-SFI [ME] control unit (N3/10) (gasoline engine).

The position of the brake pedal is recorded by the pedal angle sensor (B37/1). The Electronic Stability Program control unit (N30/4) reads in the signals of the pedal angle sensor directly and transmits the status of the brake pedal via chassis FlexRay, powertrain control unit and drive train CAN to the fully integrated transmission control unit and to the CDI control unit or to the ME-SFI [ME] control unit.

IMPORTANT With a change from circuit 15 ON to circuit 15C ON or circuit 15C OFF, if the vehicle drives or rolls, the transmission control automatically switches into transmission position "N". The vehicle can roll "freely".

Key-P, general 

Key-P comprises all the functions which in addition to the parking brake serve to secure the vehicle to prevent it from rolling away unintentionally. The Key-P function includes the following functions:

Park pawl 

The park pawl only permits switching from transmission position "P" via the DIRECT SELECT lever (S16/13) with status circuit 15 On and the brake pedal pressed.

The steering column tube module control unit (N80) reads in the DIRECT SELECT lever switch position directly and sends it over the chassis FlexRay, powertrain control unit and the drive train CAN to the fully integrated transmission control unit. The fully integrated transmission control unit then controls engagement of the selected gear range.

IMPORTANT The transmitter key (A8/1) can only be removed from the electronic ignition lock control unit after shutting off the vehicle if the switch position "P" has been engaged. The vehicle is secured mechanically by blocking the park pawl gear in the transmission.

IMPORTANT Transmission 724.2 in model 205, 253

with code 889 (KEYLESS-GO)

Transmission 724.2 in model 205, 253

with code 893 (KEYLESS-GO)

If the driver opens the driver door after switching off the engine, the transmission control shifts into transmission position "P". The left front door control unit (N69/1) sends the status of the driver door (open or closed) over the interior CAN (CAN B), electronic ignition lock control unit, chassis FlexRay, powertrain control unit and the drive train CAN to the fully integrated transmission control unit. The fully integrated transmission control unit then controls engagement of transmission position "P".

Locking of selector lever position "P" 

A gear range change from the "P" position cannot be executed if the following conditions are fulfilled:

IMPORTANT The electronic ignition lock control unit transmits the enable of the drive authorization system via periphery CAN (CAN PER), powertrain control unit, drive train CAN to the fully integrated transmission control unit and to the CDI control unit or to the ME-SFI [ME] control unit.

  Electrical function schematic, Key-P   PE27.19-P-2058-97FBH
  Overview of system components for automatic transmission hybrid drive   GF27.10-P-9993RFH 
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